Zach Yadegari, who co-founded the viral calorie tracking app Cal AI as a teenager, has launched a new AI startup called Persona and raised $10 million in funding. Vine Ventures led the investment round, with participation from Cory Levy of Z Fellows and Collective Global. Yadegari and his team exited Cal AI earlier this year when MyFitnessPal acquired the app after it rapidly grew to generate over $30 million in annual revenue within two years. After leaving MyFitnessPal in June, Yadegari immediately began focusing on Persona alongside an unannounced co-founder.

Persona aims to create a personal AI assistant device similar to offerings like Instinct and Muse but distinguishes itself with a $179 wearable band. Unlike some ambient AI wearables that continuously listen, this device activates only by a physical button or a wrist flick. The assistant runs its AI in the cloud rather than locally, prioritizing user privacy with encrypted data transmission and storage and allowing users to delete their information. The startup also incorporates strong security measures to prevent phishing and prompt-injection attacks common in AI agents.

Early versions of Persona are currently available as a free iMessage-based text assistant, with a few thousand beta users engaged. Preorders for the wearable band have already brought in five-figure revenue, and the company plans to start shipping the bands in December. Persona’s AI assistant can handle a variety of daily tasks such as ordering food, booking rides and travel, managing emails, and taking notes. Yadegari envisions Persona ultimately evolving into a proactive super app that anticipates users’ needs seamlessly without constant screen interaction.

The business model includes showing sponsored products subtly during shopping queries, although Yadegari emphasizes the AI will provide unbiased recommendations based on user preferences. Payments initiated by the assistant require explicit approval and use secure external providers like Stripe Link. As Yadegari prepares to speak at TechCrunch Disrupt in October, Persona is positioning itself as a privacy-first, secure alternative in the growing field of personal AI assistants enhanced by wearable hardware.